Graphic display systems

Abstract

A display system is disclosed for depicting a moving image of a graphic representation of a sequence of, for example, letters, words, symbols or artwork. The system comprises a display area defined by an array of light emitting diodes (LED's) which form a matrix having a series of rows and columns. The LED's are arranged in rows parallel to the intended direction of movement of an image and the columns are arranged orthogonal to the intended direction of movement. The LED's are further arranged in first and second groups in an interlacing fashion, wherein successive LED's of the first and second groups are spaced apart by one or more columns which do not contain LED's. A controller is further included for generating a plurality of electrical signals in sequential groups, each such group of signals representing encoded data of a sample portion of the graphic to be represented by one column of the matrix at a prescribed instant, and successive groups of the sets of data providing further encoded data of successive sample portions of the graphic to be represented by a column and successive prescribed instants. The system is capable of displaying high-definition graphics with only a fraction of the picture elements necessary in prior art systems, and yet which produces an image that does not tend to break up into momentary fragments, jitter, or wobble.

We claim: 
     
       1. A display system for depicting a moving image of a graphic of the type herein defined comprising: (i) a display means having a display area and an activating means; said display area being defined by an array of first and second groups of elements arranged in the form of a matrix having a series of rows and columns, each element of said first and second groups forming a cell of the matrix, said rows being arranged parallel to the intended direction of movement of said image and said columns being arranged orthogonal to said intended direction of movement; and wherein said element of said first and second groups is an image source operable to emit an image, said image being a portion of said graphic on activation thereof, said first group of elements located in selected rows of said matrix, wherein successive elements of said first group in the same row are spaced apart by one or more columns having a group of coplanar, non-image source elements in said same row which do not emit a portion of said graphic, and a second group of elements of similar formation to said first group of elements but located in other selected rows of said matrix, wherein said second group of elements are disposed in interlacing fashion relative to said first group such that one element of said second group is disposed intermediate to a pair of successive elements of said first group in an adjacent row to the row of said one element, and a cell occupied by an image source in one said group of elements partially overlaps with an immediately adjacent cell in the same column, said adjacent cell being defined by a non-image source element disposed in a row of another said group of elements; and said activating means being associated with each of said image sources to activate an image source in response to the generation of a corresponding electrical signal; and   (ii) a controller means for generating a set of said electrical signals in sequential groups, each set providing encoded data of a sample portion of said graphic to be represented by one column of said matrix at a prescribed instant, and successive groups of said sets providing further encoded data of successive sample portions of said graphic to be represented by said one column at successive prescribed instants, the period between successive prescribed instants being a display state period of said image, said encoded data being sequentially provided to be represented by successive columns of said matrix at said successive prescribed instants, wherein only those rows of image sources within a column of said matrix are activated for which an electrical signal has been generated in accordance with said encoded data.   
     
     
       2. A display system as claimed in claim 1, wherein said display state period is typically 8 milliseconds. 
     
     
       3. A display system as claimed in claim 1, wherein the image sources are arranged in discrete lines within selected columns, orthogonal to the intended direction of movement of said image. 
     
     
       4. A display system as claimed in claim 1, wherein said successive image sources within the same row are spaced apart by equal intervals of said non-image source elements. 
     
     
       5. A display system as claimed in claim 4, wherein said equal interval of non-image source elements may number up to 20 columns of non-image source elements in said row, and is typically 7 to 14. 
     
     
       6. A display system as claimed at claim 1, wherein said controller means includes computing means having memory means, control means and communication means, said memory means having facility for storage of a reference set of graphic characters in the form of groups of encoded data located in a look-up table, from which relevant encoded data may be provided to said display means in respect of a particular graphic which is desired to be displayed at said display area in response to a communication received by said communication means. 
     
     
       7. A display system as claimed in claim 1 wherein said activating means includes a storage means for a column of said matrix having an image source, said storage means having a storage element of each element in said column, and an activating circuit means to activate said image source in response to the generation of an actuating signal by said controller means, whereby a set of encoded data prescribed for said column is stored within said storage means prior to commencement of a display state period and said image source is activated in response to said actuating signal, dependent upon whether a said electrical signal is stored within the storage element corresponding to said image source on commencement of said display state period. 
     
     
       8. A display system as claimed in claim 7, wherein said activating means includes a further storage means associated with one or more successive columns not having an image source disposed therein and having a further storage element for each element in said associated column, whereby by a set of encoded data prescribed for said associated column is stored within said storage means prior to commencement of a display state period and transferred to a successive storage means on completion of said display state period and prior to the commencement of the next display state period. 
     
     
       9. A method of depicting a moving image of a graphic of the type herein defined on a display means having a display area being defined by an array of elements arranged in the form of a matrix having a series of rows and columns, each element forming a cell of the matrix, and rows being arranged parallel to the intended direction of movement of said image and said columns being arranged orthogonal to said intended direction of movement; a first group of elements, each element of said first group being an image source operable to emit a portion of said graphic on activation thereof, said first group of elements located in selected rows of said matrix, wherein successive elements of said first group in the same row are spaced apart by one or more columns having non-image source elements in said same row which do not emit a portion of said graphic, and a second group of elments of similar formation to said first group of elements but located in other selected rows of said matrix, wherein said second group of elements are disposed in a coplanar and interlacing fashion relative to said first group such that one element of said second group is disposed intermediate a pair of successive elements of said first group in an adjacent row to the row of said one element, and a cell occupied by an image source in one set group of elements partially overlaps with an immediately adjacent cell in the same column, said adjacent cell being defined by a non-image source element disposed in a row of another said group of elements; and said activating means being associated with each of said image sources to activate an image source in response to the generation of a corresponding electrical signal, the method comprising the steps of generating a set of said electrical signals in sequential groups, each set providing encoded data of a sample portion of said graphic to be represented by one column of said matrix at a prescribed instant, and successive groups of said sets providing further encoded data of successive sample portions of said graphic to be represented by said one column at successive prescribed instants, the period between succesive prescribed instants being a display state period of said image, said encoded data being sequentially provided to be represented by successive columns of said matrix at said successive prescribed instants, wherein only those rows of image sources within a column of said matrix are activated for which an electrical signal has been generated in accordance with said encoded data. 
     
     
       10. A method as claimed at claim 9, wherein said display state period is typically 8 milliseconds. 
     
     
       11. A method as claimed at claim 9, wherein the image sources are arranged in discrete lines within selected columns, orthogonal to the intended direction of movement of said image. 
     
     
       12. A method as claimed in claim 9, wherein said successive image sources within the same row are spaced apart by equal intervals of said non-image source elements. 
     
     
       13. A method as claimed in claim 12, wherein said equal interval of non-image source elements may number up to 20 columns of non-image source elements in said row, and is typically 7 to 14. 
     
     
       14. A method as claimed in claim 9, wherein the method includes providing relevant encoded data to said display means in respect of a particular graphic which is desired to be displayed at said display area in response to a communication received by a communication means by obtaining said relevant encoded data from a memory means having facility for storage of a reference set of graphic characters in the form of groups of encoded data located in a look-up table. 
     
     
       15. A method as claimed in claim 9, wherein the activating means includes a storage means for a column of said matrix having an image source, said storage means having a storage element for each element in said column, and an activating circuit means to activate said image source in response to the generation of an actuating signal by said controller means, whereby a set of encoded data prescribed for said column is stored within said storage means prior to commencement of a display state period and said image source is activated in response to said actuating signal, dependent upon whether a said electrical signal is stored within the storage element corresponding to said image source on commencement of said display state period. 
     
     
       16. A method as claimed in claim 15, wherein said activating means includes a further storage means associated with one or more successive columns not having an image source disposed therein and having a further storage element for each element in said associated column, whereby a set of encoded data prescribed for said associated column is stored within said storage means prior to commencement of a display state period and transferred to a successive storage means on completion of said display state period and prior to the commencement of the next display state period.